Sperm concentration and fertilization rate in Bufo arenarum (Amphibia: Anura)

1975 ◽  
Vol 62 (2) ◽  
pp. 481-486
Author(s):  
M. O. Cabada
Keyword(s):  
Sperm Concentration ◽  
Fertilization Rate ◽  
Experimental Results ◽  
General Validity ◽  
Psammechinus Miliaris ◽  
Bufo Arenarum

The influence of sperm concentration upon the fertilization rate of Bufo arenarum oocytes was determinated. The experimental results were analysed according to the theories of Rothschild and Swann, and Hultin and Hagstrom for Psammechinus miliaris. The experimental results agreed with the predictions of the latter theory. Since Bufo arenarum and Psammechinus miliaris oocytes differ in both size and disposition of jelly envelopes, the postulations of Hultin and Hagstrom's theory appear to have a general validity.

scholarly journals Difficulties in Comprehending Affirmative and Negative Sentences: Evidence From Chinese Children With Reading Difficulties

2017 ◽  
Vol 51 (2) ◽  
pp. 181-193 ◽  
Author(s):  
Shenai Hu ◽  
Maria Vender ◽  
Gaetano Fiorin ◽  
Denis Delfitto
Keyword(s):  
Mandarin Chinese ◽  
Reading Difficulties ◽  
Judgment Task ◽  
Experimental Results ◽  
Chinese Children ◽  
Behavioral Data ◽  
Poor Readers ◽  
Value Judgment ◽  
General Validity ◽  
Truth Value

Recent experimental results suggest that negation is particularly challenging for children with reading difficulties. This study looks at how young poor readers, speakers of Mandarin Chinese, comprehend affirmative and negative sentences as compared with a group of age-matched typical readers. Forty-four Chinese children were tested with a truth value judgment task. The results reveal that negative sentences were harder to process than affirmative ones, irrespective of the distinction between poor and typical readers. Moreover, poor readers performed worse than typical readers in comprehending sentences, regardless of whether they were affirmative or negative sentences. We interpret the results as (a) confirming the two-step simulation hypothesis, based on the result that the difficulty in processing negation has a general validity (persisting in pragmatically felicitous contexts), and (b) disconfirming that negation, as far as behavioral data are concerned, can be used as a reliable linguistic predictor of reading difficulties.

The Onset of Whirl Instability in Journal Bearings of Various Bore Shapes and Groove Sizes

1983 ◽  
Vol 105 (3) ◽  
pp. 342-352 ◽  
Author(s):  
M. Akko¨k ◽  
C. M. McC. Ettles
Keyword(s):  
Beneficial Effect ◽  
Load Capacity ◽  
Journal Bearings ◽  
Experimental Results ◽  
General Validity ◽  
Model Based ◽  
Linearized Model ◽  
Varying Viscosity

Experimental results are given for load capacity and whirl onset in journal bearings of circular, elliptical and offset halves bore shape. The general validity of the linearized model for predicting whirl is confirmed experimentally. Deviations between experimental results and the model, based on an isoviscous film, are attributed to the varying viscosity that occurs in practice, and to unavoidable excitation that gives rise to premature whirl. It is shown that increasing groove size has a destabilizing effect that can more than cancel the beneficial effect of preloading. This result is particularly relevant to the design of journal bearings in turbomachinery.

P–031 The effect of ejaculatory abstinence period on embryological and clinical outcomes in ICSI cycles: A retrospective analysis of 3,353 cycles

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
G C Cermisoni ◽  
L Pagliardini ◽  
A Alteri ◽  
L D Santis ◽  
S Esposito ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Live Birth ◽  
Sperm Quality ◽  
Sperm Concentration ◽  
Live Birth Rate ◽  
Fertilization Rate ◽  
Ongoing Pregnancy ◽  
Abstinence Period ◽  
Blastulation Rate ◽  
Ejaculatory Abstinence

Abstract Study question Does ejaculatory abstinence period in male affect embryological and pregnancy outcomes following fresh embryo transfers in ICSI cycles? Summary answer Shorter ejaculatory abstinence period is associated with lower triploid zygotes rate per ICSI cycle but it does not affect clinical outcomes after fresh embryo transfers. What is known already Lower sperm quality may negatively impact on fertilisation rate and embryo morphokinetic parameters after ICSI and the effect of the ejaculatory abstinence period before semen collection on seminal parameters and sperm quality has been widely reported. However, the impact of ejaculatory abstinence on clinical outcomes is still controversial. WHO (World Health Organization) guideline recommended that abstinence period should be 2–7 days. Even so, there are no larger prospective trials determining the optimal timing for ejaculatory abstinence period for infertile couples. Study design, size, duration This is a single center retrospective observational study of 3,353 fresh cycles from January 2017 to December 2020. Semen analysis was done according to the WHO criteria. Exclusion criteria for this study were frozen gametes and cycles with no retrieved oocytes. Primary outcomes were fertilization rate and triploid zygotes rate. Secondary outcomes were blastulation rate, ongoing pregnancy rate and live birth rate per fresh embryo transfer. Participants/materials, setting, methods The correlation between ejaculatory abstinence and continuous outcomes was evaluated by Spearman’s correlation analysis in order to detect potential non-linear associations. Generalized linear model and logistic regression were used, respectively for continuous and binary outcomes, in order to adjust for confounders such as female age, male age, number of retrieved oocytes, percentage of mature oocytes, infertility causes, seminal volume, sperm concentration and total progressive sperm motility. A p value <0.05 was considered significant. Main results and the role of chance The male mean age was 40.3±5.5 and mean duration of abstinence was 2.9±1.7 days. The mean age of female patients was 38.2±4.0. Higher ejaculatory abstinence period was associated with a higher sperm concentration (Spearman p = 3.1x10–6) but not with a higher total sperm progressive motility. Even so, no significant correlation with EA were observed when considering fertilization rate, blastulation rate, ongoing pregnancy and live birth rate per transfer in analyzed cycles. Triploid zygote rate was positively associated with a higher ejaculatory abstinence period. For the ejaculatory abstinence period of 1 day (n = 64), 2 days (n = 1523), 3 days (n = 1032), 4 days (n = 408), 5 days (n = 174), 6 days (n = 47) and ≥7 days (n = 105) the mean triploid rate was 2.4%, 2.4%, 2.5%, 4.1%, 3.6%, 5.4% and 4.3%, respectively (Spearman p = 9x10–3). Triploid zygote rate was independent of semen volume, concentration and total progressive motility. Limitations, reasons for caution This is a large observational study with a retrospective data collection. Despite our methodological approach, the presence of biases related to retrospective design can not be excluded and it may be a reason for caution. Wider implications of the findings: Our results demonstrate that ejaculatory abstinence period do not affect blastulation, ongoing pregnancy and live birth rates. The current findings discourage an abstinence time longer than 3 days due to its association with a higher abnormal fertilization rate. Trial registration number Not applicable

Effect of time of ovulation and sperm concentration on fertilization rate in gilts

2003 ◽  
Vol 60 (4) ◽  
pp. 669-676 ◽  
Author(s):  
C.J Bracken ◽  
T.J Safranski ◽  
T.C Cantley ◽  
M.C Lucy ◽  
W.R Lamberson
Keyword(s):  
Sperm Concentration ◽  
Fertilization Rate

scholarly journals Embryonic, Larval, and Early Juvenile Development of the Tropical Sea Urchin,Salmacis sphaeroides(Echinodermata: Echinoidea)

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
M. Aminur Rahman ◽  
Fatimah Md. Yusoff ◽  
A. Arshad ◽  
Mariana Nor Shamsudin ◽  
S. M. N. Amin
Keyword(s):  
Sea Urchins ◽  
Morphological Changes ◽  
Sperm Concentration ◽  
Fertilization Rate ◽  
Life History Strategies ◽  
Early Juvenile ◽  
Culture Techniques ◽  
Unicellular Algae ◽  
Tropical Sea ◽  
Juvenile Development

Salmacis sphaeroides(Linnaeus, 1758) is one of the regular echinoids, occuring in the warm Indo-West Pacific, including Johor Straits, between Malaysia and Singapore. In order to investigate the developmental basis of morphological changes in embryos and larvae, we documented the ontogeny ofS. sphaeroidesin laboratory condition. Gametes were obtained from adult individuals by 0.5 M KCl injection into the coelomic cavity. Fertilization rate at limited sperm concentration (10−5dilution) was96.6±1.4% and the resulting embryos were reared at 24°C. First cleavage (2-cell), 4-cell, 8-cell, 16-cell, 32-cell, and multicell (Morulla) stages were achieved 01.12, 02.03, 02.28, 02.51, 03.12, and 03.32 h postfertilization. Ciliated blastulae with a mean length of174.72±4.43 μm hatched 08.45 h after sperm entry. The gastrulae formed 16.15 h postfertilization and the archenteron elongated constantly while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larva started to feed unicellular algae in 2 d, grew continuously, and finally attained metamorphic competence in 35 d after fertilization. Metamorphosis took approximately 1 h 30 min from attachment to the complete resorption of larval tissues and the development of complete juvenile structure with adult spines, extended tubefeet and well-developed pedicellaria, the whole event of which usually took place within 1 d postsettlement. This study represents the first successful investigation on embryonic, larval, and early juvenile development ofS. sphaeroides. The findings would greatly be helpful towards the understanding of ontogeny and life-history strategies, which will facilitate us to develop the breeding, seed production, and culture techniques of sea urchins in captive condition.

scholarly journals IVF and Early Pregnancy Outcome in Recent COVID 19 Recoverees.

2021 ◽  
Author(s):  
Kabalkin B. Yossef ◽  
Yaakov Bentov ◽  
Moran Gil ◽  
Ofer Beharier ◽  
Sireen Jaber ◽  
...  
Keyword(s):  
Hospital Admissions ◽  
Sperm Quality ◽  
Endometrial Thickness ◽  
Male Partner ◽  
Sperm Concentration ◽  
Ovarian Response ◽  
Fertilization Rate ◽  
Obstetric Outcomes ◽  
Post Exposure ◽  
Before And After

Abstract Background: COVID-19 global pandemic has affected more than 250 million people so far. Data regarding potential effects on reproduction are still limited. Our aim was to examine the effect of COVID-19 on post exposure IVF cycle parameters and obstetric outcomes of IVF-achieved pregnancies.The study contained two arms: a retrospective arm comparing IVF outcome parameters among patients exposed to COVID-19 having an IVF cycle within 3 months of exposure. Post COVID-19 cycle parameters were compared to previous cycles of the same individual, performed within one year of exposure. If not available, parameters were compared to non-exposed matched patients. Sperm parameters were compared before and after exposure. The second arm was prospective comparing pregnancy outcomes among IVF patients who contracted COVID-19 during pregnancy, vs. those who did not. Results: The first arm included 120 cycle of which 60 were in exposed female patients and another 60 in either the same patients prior to exposure or matched non exposed patients. Generally, total FSH dose, cycle length, and ovarian response did not significantly differ across exposure groups: including peak serum estradiol, number of oocytes and endometrial thickness, fertilization rate and number of top-quality embryos, were similar between exposed and non-exposed cycles. In 11 of the cycles in which the female partner was exposed the male partner had been recently exposed as well. In these couples, sperm quality showed a significantly lower post-exposure concentration: 6.27million/ml vs. 16.5 (p= 0.008). Interviews conducted in 189 patients with IVF-achieved pregnancies: pregnancy loss was as well as other pregnancy related complications and hospital admissions did not differ between groups. Conclusion: IVF treatment parameters and IVF-achieved pregnancies appear to be unaffected by SARS-CoV-2 exposure and do not involve an excess risk. Sperm concentration seems to be compromised.

scholarly journals A Simple and Efficient Semen Cryopreservation Method to Increase the Genetic Variability of Endangered Mediterranean Brown Trout Inhabiting Molise Rivers

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 403
Author(s):  
Giusy Rusco ◽  
Michele Di Iorio ◽  
Roberta Iampietro ◽  
Stefano Esposito ◽  
Pier Paolo Gibertoni ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Brown Trout ◽  
Sperm Concentration ◽  
Mediterranean Area ◽  
Fertilization Rate ◽  
Semen Cryopreservation ◽  
Nitrogen Vapor ◽  
C 30

The aim of our study was to test the effectiveness of a simple semen cryopreservation procedure, developed for cultivated salmonid, on the wild salmonid of the Mediterranean area and to evaluate the effect of different thawing rates and sperm-to-egg ratios. The semen of five individual males was diluted into a final extender concentration of 0.15 M glucose and 7.5% methanol and loaded into 0.25 mL plastic straws, and a final sperm concentration of 3.0 × 109 sperm/mL was obtained. After equilibration, the straws were frozen by exposure to liquid nitrogen vapor at 3 cm above the liquid nitrogen level for 5 min. The semen was thawed at 40 °C/5 s or 10 °C/30 s. The sperm cryosurvival was evaluated by examining in vitro the sperm motility parameters using the CASA system, followed by fertilization trials in vivo, using three different sperm-to-egg ratios 6 × 105, 4.5 × 105 and 3 × 105:1. The applied cryopreservation procedure resulted in remarkably high (85.6%) post-thaw sperm total motility, when the semen was thawed at 40 °C/5 s, whilst the highest fertilization rate (53.1%) was recorded for a sperm-to-egg ratio of 4.5 × 105:1. According to these outcomes, the cryopreservation procedure that was tested turned out to be effective for the wild population of Mediterranean brown trout and practical for the creation of the first European semen cryobank foreseen as part of our “LIFE” Nat.Sal.Mo. project.

Participation of the 39-kDa glycoprotein (gp39) of the vitelline envelope of Bufo arenarum eggs in sperm–egg interaction

Zygote ◽  
2011 ◽  
Vol 20 (2) ◽  
pp. 159-171 ◽  
Author(s):  
Daniel Barrera ◽  
Ricardo J. Llanos ◽  
Dora C. Miceli
Keyword(s):  
Binding Capacity ◽  
Polyclonal Antibodies ◽  
Fertilization Rate ◽  
Sperm Head ◽  
Binding Assays ◽  
Sperm Binding ◽  
Sds Page ◽  
Bufo Arenarum ◽  
Pars Recta ◽  
Vitelline Envelope

SummaryThe acquisition of egg fertilizability in Bufo arenarum takes place during the oviductal transit and during this process the extracellular coelomic envelope (CE) of the eggs is converted into the vitelline envelope (VE). It has been stated that one of the necessary events leading to a fertilizable state is the proteolytic cleavage of CE glycoproteins in the oviductal pars recta by oviductin, a serine protease. Consequently, there is a marked increase in the relative quantity of glycoproteins with 39 (gp39) and 42 kDa (gp42) in the VE. In the present study, sperm–VE binding assays using heat-solubilized biotin-conjugated VE glycoproteins revealed that both gp39 and gp42 have sperm binding capacity. According to this result, our study was focused on gp39, a glycoprotein that we have previously reported as a homologue of mammalian ZPC. For this purpose, rabbit polyclonal antibodies against gp39 were generated at our laboratory. The specificity of the antibodies was confirmed with western blot of VE glycoproteins separated on SDS-PAGE. Immunohistochemical and immunoelectron studies showed gp39 distributed throughout the width of the VE. In addition, immunofluorescence assays probed that gp39 bound to the sperm head. Finally, as an approach to elucidate the possible involvement of gp39 in fertilization, inhibition assays showed that pretreatment of eggs with antibodies against gp39 generated a significant decrease in the fertilization rate. Therefore, our findings suggest that gp39, which is modified by oviductal action, participates as a VE glycoprotein ligand for sperm in Bufo arenarum fertilization.

167 INFLUENCE OF THE SPERM SELECTION METHOD AND FERTILIZATION DOSES ON CHROMOSOMAL ABNORMALITY RATES OF 4-DAY-OLD BOVINE EMBRYOS

2012 ◽  
Vol 24 (1) ◽  
pp. 195
Author(s):  
S. Demyda Peyrás ◽  
L. J. De Luca ◽  
M. Moreno Millán
Keyword(s):  
Chromosomal Abnormality ◽  
Chromosomal Abnormalities ◽  
Cytogenetic Study ◽  
Sperm Concentration ◽  
Fertilization Rate ◽  
Selection Method ◽  
Sperm Selection ◽  
Bovine Embryos ◽  
Fertilization Rates

This cytogenetic study was conducted to quantify the incidence and type of chromosomal abnormalities on in vitro-produced bovine embryos. Eight groups of 150 in vitro-matured oocytes were IVF for 18 h. Final sperm concentrations of 1 × 104, 1 × 105, 1 × 106 and 1 × 107 cells mL–1 selected by the washing method or the swim-up method were utilised. Presumptive zygotes were cultured for 96 h, collected and fixed individually for analysis. Chromosomal complements of 447 embryos were determined by Giemsa staining and direct observation. Rates of haploidy, diploidy, aneuploidy and polyploidy were determined individually. The incidence of chromosomal abnormalities in embryos derived by IVF with 1 × 104, 1 × 105 and 1 × 106 cells mL–1 did not differ regardless of the sperm preparation method. Polyploidy incidence was strongly increased (P < 0.01) at a concentration of 1 × 107 cells mL–1 in both sperm treatment groups. The fertilization rate obtained with a 1 × 104 cells mL–1 sperm dose in both selection methods and with a 1 × 105 cells mL–1 sperm dose with the washing selection method were significantly lower (P < 0.05) than those obtained with the other sperm concentrations. The lowest fertilization rates (P < 0.05) were achieved with the lowest dose and the washing sperm selection technique. Acceptable fertilization rates with low chromosomal abnormalities can be achieved with a final sperm concentration of 1 × 105 cells mL–1 or higher regardless of the sperm selection method used. In conclusion, the sperm selection method did not result in differences in the chromosomal abnormality rates on in vitro-produced bovine embryos. The use of high sperm concentration doses produced unacceptable rates of such abnormalities regardless of the sperm selection method. The use of very low sperm doses produced unacceptable fertilization rates, especially when the washing sperm selection method was performed. Sebastián Demyda Peyrás is an MAEC–AECID grantee.

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